An impact sprinkler head can be spiked into the ground or placed on the ground, depending on the base, to water a desired segment of lawn or garden. A water hose connects to the side of the sprinkler and activates the sprinkler head when it's turned on. The sprinkler head can be adjusted to water within a certain range. After the water sprinkler is set up, you might encounter a problem with non-oscillation.
If the water pressure going through the impact sprinkler head is too high or too low, the sprinkler head won't rotate; it will stay in only one position. To determine the water pressure, place a pitot tube pressure gauge into the water stream coming out of the spray head as close to the nozzle as possible. Depending on the water pressure reading, correct the issue at the water source.
If the impact sprinkler head turns in a consistent circle but doesn't oscillate or move back and forth, the trip pin, the thin piece of metal located at the base of the impact sprinkler just above the two trip collars, must be raised. Lower the trip pin between the two trip collars to set the sprinkler to oscillate. Oscillation causes the sprinkler head to water within a rotation range, whereby the head moves back and forth between set boundaries as it waters.
The trip collars are located below the trip pin at the base of the sprinkler head. They set the boundaries for the watering range. The tip pin activates the boundaries outlined by the trip collars when lowered between them. The trip collars are usually metal or plastic and can be adjusted by pushing them with your fingers or pinching the two prongs and rotating them until they each align with the left and right edges of the watering area. If the trip collars are too close together, the sprinkler head might be restricted to one direction and not oscillate properly.
Avoid adding any kind of lubricants to the impact sprinkler head. This might temporarily fix the problem but will damage and disengage the sprinkler head in no time. Lubricants to avoid include oil, WD-40, Teflon, silicone and pipe dope. The lubricant causes the head to move easily when applied but quickly attracts dust and dirt into the washers and bearing stack. The friction caused by the accumulation of debris wears down the sprinkler head considerably, and parts will need to be replaced.